Gerwyn Price defeats world number nine Danny Noppert
Gerwyn Price defeated world number nine Danny Noppert in straight sets, and the 2020 champion will now face Krzysztof Ratajski, who came from behind to knock out two-time winner James Wade.
The first round continues on Tuesday night, as Michael van Gerwen begins his bid for a seventh World Grand Prix title against debutant Josh Rock.
Former champions Jonny Clayton and Daryl Gurney are in action, along with world number three Peter Wright, two-time runner-up Dave Chisnall and fifth seed Luke Humphries.
Last year's runner-up Aspinall and eighth seed Cross were both beaten in dramatic last-leg deciders at the hands of Stephen Bunting and Andrew Gilding respectively, as the double-start event got underway with eight first round clashes at the Morningside Arena.
Bunting, a two-time World Grand Prix semi-finalist, produced a strong deciding leg against Aspinall to continue his impressive record in the event.
"Neither of us were at our best tonight but when you get through like that you don't really look at the performance," Bunting reflected.
"It was a very nervous game all the way through. I started really well but in the second set I lost a bit of composure.
"I was praying that I hit my starting double first dart in the decider; thankfully I did and now I'm looking forward to the next round.
"I think I'm playing the darts of my life at the moment so I'm full of confidence."
Bunting's second round assignment will see him take on Martin Schindler, after the German number two enjoyed a first World Grand Prix win over two-time runner-up Raymond van Barneveld.
UK Open champion Gilding overcame a slow start to claim a first World Grand Prix victory in nine years and make it a fifth first round exit in seven outings for Cross.
Gilding's victory sees him set up a round two meeting with Gary Anderson, as the resurgent Scot impressed in a 2-1 victory over Jose de Sousa.
"It was a hard one, that's the best I've seen Jose play for a while," said Anderson.
"I've got a lot of time for Jose, we spent a lot of time practicing together the last time we were both in the Premier League and I know how good he can be.
"I don't put any pressure on myself anymore, I'm just enjoying playing darts right now and I'll see where it takes me."
Michael Smith produced the performance of the night, averaging 96.14 in a 2-0 defeat of Callan Rydz, and the top seed will now face 2011 runner-up Brendan Dolan, who took the scalp of Dirk van Duijvenbode.
Click here for match statistics.
2023 BoyleSports World Grand Prix
Monday October 2
First Round x8
Brendan Dolan 2-1 Dirk van Duijvenbode (0-3, 3-1, 3-0)
Gary Anderson 2-1 Jose de Sousa (2-3, 3-0, 3-2)
Krzysztof Ratajski 2-1 James Wade (1-3, 3-0, 3-2)
Martin Schindler 2-1 Raymond van Barneveld (3-2, 2-3, 3-1)
Stephen Bunting 2-1 Nathan Aspinall (3-1, 2-3, 3-2)
Gerwyn Price 2-0 Danny Noppert (3-2, 3-0)
Michael Smith 2-0 Callan Rydz (3-0, 3-1)
Andrew Gilding 2-1 Rob Cross (0-3, 3-1, 3-2)
Tuesday October 3 (1800 BST)
First Round x8
Joe Cullen v Mike De Decker
Dave Chisnall v Luke Woodhouse
Damon Heta v Ryan Searle
Dimitri Van den Bergh v Chris Dobey
Peter Wright v Gabriel Clemens
Michael van Gerwen v Josh Rock
Jonny Clayton v Ross Smith
Luke Humphries v Daryl Gurney
Wednesday October 4 (1900 BST)
Second Round x4 – Match Order TBC
Michael Smith v Brendan Dolan
Andrew Gilding v Gary Anderson
Gerwyn Price v Krzysztof Ratajski
Stephen Bunting v Martin Schindler
Thursday October 5 (1900 BST)
Second Round x4 – Match Order TBC
Van Gerwen/Rock v Van den Bergh/Dobey
Clayton/R Smith v Cullen/De Decker
Wright/Clemens v Heta/Searle
Humphries/Gurney v Chisnall/Woodhouse
Friday October 6 (1900 BST)
Quarter-Finals
Saturday October 7 (2000 BST)
Semi-Finals
Sunday October 8 (2000 BST)
Final